Arrangement for recording, reproducing, and printing films



June 1, 1937. H. LIEDTKE ET AL ARRANGEMENT FOR RECORDING, REPRODUCING, AND PRINTING FILM Filed June 12, 1935 mvENToRs HANS LIEDTKE HERMANN EEESE A fl D'; aw l/ ATTORNEY Patented June 1, 1937 ARRANGEMENT FOR RECORDING, REPRO DUCING. AND PRINTING FILMS Hans Licdtke and Herman Freese, Berlin, Germany, assignors to Klangfilm G. in. b. H,

Berlin, Germany, a corporation of Germany Application June 12,

m5, Serial No. 26,174

In Germany July 25, 1934 4 Claims.

It is known from the photographic art of recording, reproducing or printing sound record films or the like, to cause the film strip at the pick-up or recording or exposure point to run over a smooth roller coupled rigidly with a fiywheel, the film strip being pulled by a sprocket wheel over the smooth roller to transmit all or substantially all of the driving torque of the flywheel. Between the said sprocket wheel and the smooth roller is disposed an elastic film tensioning roller which has its movement damped by suitable means. Between the supporting lever of the film tensionlng roller and the said damping or smoothing meansv it has been customary to interpose a special spring with a view to permitting the film tensioning roller to move slightly without damping under certain conditions such as the feeding of shrunk films.

The present invention is concerned with constructing the damping means itself in such a way that the film tensioning roller will be capable of undergoing slight movements without damping.

The invention will be better understood from the following description when considered in connection with the accompanying drawing, and

25 its scope will be pointed out in the appended claims.

Referring to the drawing:

Fig. 1 illustrates .a form of the invention wherein a vented dashpot is provided to permit 30 slight undamped movement of the film tensioning roller,

Fig. 2 illustrates certain details of a suitable form of dashpot, and r r Fig. 3 illustrates a modified form of damper 35 adapted to be mounted at the pivotal axis of the film tensioning roller. Referring to Fig. 1, l0 denotes the film strip, I l is the fly-wheel which is coupled to the smooth roller l2, while i3 and I4 designate the sprocket 40 wheel and the yielding film-tensioning roll. United with the lever l5 of the film tensionlng roll is the pistonoi' a'dashpot II. The cylinder of I! itself is pivoted at l8. l

The damping cylinder I! may consist of an 45 air dashpot which permits slight movements of the piston IS with incidental compression of the volume of air confined inside the cylinder II, in other words, without any appreciable air current being permitted to flow through the vent I9 50 of the said cylinder. The provision of this particular klnd of damping devicexmakes the disv position of a distinct yielding intermediate link between tensloning roll lever l5 and the piston l6 unnecessary. 55 The air damping or dashpot device is preferably sodesigned, as shown in Fig. 2, that the aperture or vent l9 is'arranged in the stem of the piston l6, and that by the aid of a set screw it is capable of being adjusted gradually.

Another exemplified embodiment of the invention is illustrated in Fig, 3. Rigidly associated with thelever l5 at its pivoting point is a part play or backlash. For this, purpose part 23 is furnished with arecess 24; The part 23 in turn is rotatable about the axis 25, whereas 26 desighates the axis of the pivot of the roller tensioning lever l5 shown in Fig. 1. Rotation or pivoting of part 23 about axis 25 is possible only with a.

certain amount of friction. For this purpose a damping device 28 is interposed between the part 23 and a part 21 fixed in' space, the said damping device being preferably of the type of a liquid or fluid dashpot.

Having thus described our invention. we claim: 1. A photophonographic apparatus including means for supporting a moving record strip, means including a movable idler roller for ten sioning said strip, damping means connected to said roller, and means in cooperative relation with said damping means permitting undamped movement of said damping means only within predetermined limits of movement.

2. A photophonographicapparatus including means for supporting a moving record strip,

means including a movable idler roller for tensioningsaid strip, and means mounted at the pivotal support ofsald roller for permitting undamped movement of said rollenonly within predetermined limits.

3. A photophonographic apparatus including means for supporting and moving a record strip, means including a lever pivoted at one end and provided with an idler roller at the other end for tensioning said strip-and meansrotatable about the pivotal axis of said lever to permit undamped movement of said roller only within predetermined limits.

4. Photophonographic apparatus, including a sprocket for driving a film at predetermined speed, a drum over which the film is drawn, a fly-wheel connected to said drum for insuring that the film moves at a uniform average speed, an idler between said sprocket and said drum for absorbing difierences in movement between said sprocket and said drum, damping means and a lost-motion connection between said damping means and said idler, whereby said idler is permitted a predetermined amount of undamped motion.

HANS LIEDTKE. HERMANN FREESE. 

